[en] Calcification in primary lung carcinoma is supposed to be a rare manifestation. On chest radiography, the presence of calcification in a nodular lesion is usually evidence of benign disease. However, with the better density resolution by CT, there have been several case reports of calcified primary lung carcinomas. To better understand the scope of the problem, we reviewed CT records of 131 patients undergoing initial examinations for the lung. From this information, we were able to estimate the prevalence of calcification and to better evaluate the morphological features of calcified carcinomas. There were 12 cases with calcification (9%). Although most of the carcinomas could be differentiated from a benign process using size criteria and the morphological features of the calcification, there are still some cases (1.5%) that are difficult to discriminate from a benign process. Thus the visualization of calcium in the tumor does not always exclude the diagnosis of bronchogenic carcinoma. Small cell carcinomas had a relatively high incidence of calcification. Four of 5 squamous cell carcinomas with calcification showed solitary and punctate calcification. Small carcinomas had multiple calcifications in the center of the mass. (author)